In a turbine of the kind mentioned above, driven by gas at very high temperature, the rotor rotates inside a stationary turbine ring constituted by a plurality of curved sectors that are united end to end circumferentially in order to form the rotor shroud. The temperature of the gas driving the blade wheel is such that the thermomechanical stresses that are created between the sectors can lead to deterioration, reducing the lifetime of such rings. Typically, small cracks and/or flaking can often be observed on the inside (or “hot”) face of the sectors, mainly in the vicinity of the connections between adjacent sectors.
To provide the ring with better sealing, reducing leaks of non-working air, and in order to prevent hot gas being reinserted, sealing systems are provided between such adjacent sectors, said systems comprising tongues that extend between the sectors and that are received in slots formed facing them in the adjacent radial faces of said sectors.
For example, a prior art sector 1 shown in FIG. 1 includes a sealing system comprising four tongues 2-5 received in slots 6, 7, and 8. The tongue 3 is bent and extends between two slots 6 and 7 that open out into each other and that receive the other tongues 2 and 4 which are straight. It is difficult to machine the slots accurately, in particular because of the difference in thickness needed to be able to insert the bent tongue. It is difficult to position this tongue properly. In addition, the tongue 2 is received entirely within a slot 6 that is parallel to the hot face 9 of the sector and that is close thereto. Unfortunately, the mere fact of forming the slot leads to stress concentration zones which, when situated close to a hot surface, weaken the part and accelerate deterioration thereof. The invention makes it possible to eliminate these drawbacks, in particular.